百菌清农药残留的SPE-GC检测

对环境水样中百菌清农药残留进行了SPE-GC分析方法研究。环境水样通过Florisil柱富集、净化,3 mL乙酸乙酯洗脱,GC-ECD进行分析检测。实验表明,百菌清农药残留在0.01~10 mg/L范围内线性关系良好,相关系数为0.9993。外标法定量,检出限为0.0035 mg/L,对实际水样进行加标回收,回收率范围在93.47%~100.14%之间,6次重复测定相对标准偏差在3.97%~4.96%之间,并将方法应用于周边环境地表水的检测。该方法具有简便,快速,准确,灵敏度高等特点,能满足环境水样中农药残留分析要求。     

高效液相色谱-串联质谱法同时检测地表水中13种药物及个人护理品

采用高效液相色谱-串联质谱(HPLC-MS/MS)检测,建立了地表水中13种药物及个人护理品的测定方法。水样用盐酸与氢氧化钠溶液调p H值至7.0左右,过固相萃取小柱进行富集,用14 m L甲醇洗脱。以C18柱为分离柱,0.01%甲酸的甲醇-0.01%甲酸水溶液为流动相,目标物在10 min内分离,在0.50~250μg/L范围内,13种化合物峰面积与内标物质峰面积之比与质量浓度的线性关系良好(0.99),检出限在0.05~0.5 ng/L范围内。基质加标实验结果表明,13种化合物在水中的回收率分别在56.2%~123.2%之间(加标水平5 ng/m L)和58.0%~107.8%(加标水平50 ng/m L),相对标准偏差在1.60%~19.9%(n=6)之间。应用该方法测定了从2条纳污河流采集的10份水样,结果表明,除美托诺尔和普洛萘尔未被检出外,其余11药物的检出频率在30%~100%之间。在13种目标物质中,咖啡因的检测浓度最高达287.5ng/L,舒必利次之,为277.5 ng/L。本方法快速、准确,适用于地表水中PPCPs类的快速测定。     

SPE-HPLC法检测环境水样中的痕量三氯卡班

建立了环境水样中三氯卡班(TCC)的预处理和测定方法。考察了3种固相萃取(SPE)小柱、5种洗脱液对TCC回收率的影响。结果表明,采用ENVI-18 SPE小柱、以乙酸乙酯/乙腈(1∶1)为洗脱液、高效液相色谱仪-紫外检测器(HPLC-UV)检测,以蒸馏水为背景溶液TCC的加标回收率高达95%,仪器检出限与定量限分别为2.37与7.89μg/L。该方法用于实际环境水样,TCC加标浓度1~10μg/L,污水厂进水、出水与地表水中TCC的加标回收率分别在89.38%~96.90%、87.74%~94.34%与83.64%~94.61%之间,表明所建立的SPE-HPLC法适合城市生活污水和地表水中痕量TCC的检测。运用该方法测定实际环境水样中的TCC含量,集美污水处理厂进水与出水中TCC浓度分别为1.35与0.22μg/L;华大污水厂进水与出水中TCC浓度分别为1.05与0.53μg/L;白鹭湖水样中的TCC浓度为1.11μg/L。     

固相萃取—气相色谱质谱法测定水样中的毒死蜱及其代谢产物

建立了水样中毒死蜱及其主要代谢产物3,5,6-三氯吡啶醇(TCP)的固相萃取—气相色谱质谱检测法,即采用固相萃取对水样中的毒死蜱及其代谢产物TCP进行富集,浓缩后经双(三甲基硅烷基)三氯乙酰胺(BSTFA)衍生TCP,采用气相色谱质谱进行测定。同时,采用外标法对毒死蜱和TCP进行定量。结果表明,该方法的线性范围为20~1 000μg/L,毒死蜱和TCP的检出限分别为0.375、0.100μg/L;环境水样中的毒死蜱和TCP平均加标回收率分别为89.12%~93.44%和87.37%~90.75%,相对标准偏差(RSD)为2.79%~6.64%和1.22%~5.48%。     

反相高效液相色谱法测定污水中壬基酚聚氧乙烯醚总量

建立了固相萃取一反相液相色谱一荧光检测法分析污水中壬基酚聚氧乙烯醚总量的方法.固相萃取采用Wa-ters Oasis HLB固相萃取柱(30 μg×60 mg×3 mL),6 mL二氯甲烷/甲醇(90/10,V/V)混合溶剂洗脱,洗脱液用氮吹仪浓缩至1 mL,回收率为99.68%.采用ZORBAX Eclipse XDBC-18(4.6 mm×150 mm,5 μm)反相色谱柱,甲醇/水为流动相,流速1.0 mL/min,以每分钟增加2.5%的梯度陡度进行洗脱,流动相中甲醇比例由70%增加到100%,柱温23℃,进样量15μL.荧光检测器的激发波长230 nm,发射波长313 nm.采用外标法定量.该方法的空白加标和污水样品加标回收率均在90%以上,标准偏差小于10%,定量下限为0.97～1.90 μg/L.利用该方法分别对污水处理厂进水水样、二级处理出水水样、再生水水样进行了测定,测定结果的准确度和精密度满足痕量分析的要求.     

双水相气浮浮选光度法处理环境水样中痕量土霉素残留物

建立了一种新型分离方法--双水相气浮浮选光度法,使其处理环境水样中痕量土霉紊(OTC)残留物,研究了其工作原理,并用高效液相色谱法对该方法的可靠性进行了验证.利用自制的双水相气浮浮选装置,选择四氢呋喃作亲水有机溶剂、质量分数为10%的NaCl溶液作分相剂,NaOH溶液调节pH,将Cu2+与OTC形成的疏水配合物浮选至有机相,实现OTC与水样分离.浮选完毕后,经紫外-可见分光光度法分析,线性回归方程为A=1.532×105c+0.1230(其中:A为有机相的吸光度;c为水样的OTC摩尔浓度,mol/L),相关系数为0.9998,该方法的线性范围为4.8×10-7～7.3×10-5 mol/L,OTC加标回收率为99.5%～100.1%.     

4种重金属离子对间接火焰原子吸收光谱法测定铝的干扰

空气-乙炔间接火焰原子吸收法是我国目前运用较多且易于推广的铝检测方法,研究了Mg2+、Ca2+、Zn2+和Ni2+4种离子对此法测定0.40 mg/L Al3+的干扰情况。得出如下结论:(1)在±5%误差范围内,15.10 mg/L Mg2+、105.00mg/L Ca2+、0.23 mg/L Zn2+、0.88 mg/L Ni2+对0.40 mg/L Al3+无干扰。(2)本方法虽然操作复杂,但成本较低、灵敏度高,检测的浓度范围宽、稳定性好,加标回收率为96%~99%,检出限为0.04 mg/L,适宜测定范围为0.05~100.00 mg/L,适用于饮用水、河水及地下水中Al3+的测定。     

施粪肥土壤中抗生素的提取条件优化及残留特征

为确立高效的土壤抗生素提取条件,揭示施用粪肥土壤中抗生素的残留水平,分别采集江苏省常州市某养猪场新鲜猪粪样品6份、施用粪肥及无机肥水稻土壤样品各13份,对土壤抗生素提取液配比与超声提取时间进行筛选,利用高效液相色谱-串联质谱(HPLC-MS/MS)对生猪粪便和土壤中的四大类(四环素类、磺胺类、喹诺酮类和大环内脂类)15种抗生素含量进行检测分析。结果表明,最优提取条件选择为:提取液配比为甲醇:EDTA=1∶1,超声提取时间为10 min,四环素类抗生素的加标回收率为73.2%~93.4%,磺胺类为81.2%~101.1%,喹诺酮类为106.3%~110.8%。该养猪场猪粪与施粪肥土壤中均未检测到大环内脂类抗生素,其余各类抗生素平均残留量从高到低排序分别为:猪粪中四环素类磺胺类喹诺酮类;施粪肥土壤中四环素类喹诺酮类磺胺类,四环素类是最主要的抗生素污染物,残留量分别为猪粪中1.9~12.5 mg·kg-1、施粪肥土壤中23.9~212.4μg·kg-1;施无机肥土壤中未检测出抗生素,施粪肥土壤中的抗生素来源于生猪粪便。     

吹扫捕集-气相色谱法测定水中1,2-二氯乙烷

采用吹扫捕集、DB-624毛细管柱分离,气相色谱FID检测地表水和生活饮用水中的1,2-二氯乙烷,在0-530μg/L有较好的灵敏度和良好的线性关系,水样分析时,检测限为0.006 mg/L,加标回收率在91%-106%之间,平均相对标准偏差为3.3%。     

造纸废水生化处理出水臭氧微氧化脱色技术的研究

臭氧作为强氧化剂对有机物的氧化反应有选择性,能很快氧化分解木质素等发色有机物,中试研究了臭氧投加量、接触时间等对造纸废水生化处理出水深度处理的影响。结果表明:臭氧投加量为63.47~243.49mg/L时,COD、254nm紫外光下的吸光度(UV254)和色度去除率分别为22.61%~46.67%、22.35%~69.09%及55%~93%,其中色度有较高的去除率,即使在臭氧投加量仅为63.47mg/L时色度去除率也达到约55%;在接触时间为0.62~2.53h时,随着接触时间的延长,COD、UV254及色度去除率随之增加,而1.10h后色度去除率增加不多。以深度脱色为目标,完成了5 000m3/d的工程应用,臭氧相对投加率为0.20~0.50mg(以每毫克COD计)时,色度去除率为55.0%~84.0%。     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

The variation of street air levels of PAH and other mutagenic PAC in relation to regulations of traffic emissions and the impact of atmospheric processes

The occurrence of particle associated PAH and other mutagenic PAC was determined in 1996 in the street air of Copenhagen. In addition, particle extracts were tested for mutagenicity. The measurements were compared with previous measurements in 1992/1993. The levels had decreased in this period. The decrease was caused by an implementation of light diesel fuels for buses and the exchange of older petrol-driven passenger cars with catalystequipped new ones. About 65% of the reduction was caused by the application of the light diesel fuels. Under special conditions, chemical processes in the atmosphere produced many more mutagens than the direct emissions. The concentrations of S-PAC and N-PAC were 10 times lower than those of PAH, while the levels of oxy-PAH were in the same order of magnitude as those of PAH. Benzanthrone, an oxy-PAH, is proposed to be formed in the atmosphere in addition to direct emissions. Benzo(a)pyrene, often applied as an air quality criteria indicator, was photochemically degraded in the atmosphere. A strong increase in the mutagenic activities was observed to coincide with a depletion of benzo(a)pyrene.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Observations on the influence of water and soil pH on the persistence of insecticides

Abstract

The pH‐disappearance rate profiles were determined at ca. 25°C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water‐ethanol (99: 1 v/v). Half‐lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (>1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1–2 days for trichlorfon and oxamyl to >1 year for fensulfothion and cyper‐methrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.     

Teratological effects of pesticides in vertebrates: a review

Abstract

In the last decades, the use and misuse of pesticides in the agriculture have increased, having a severe impact on ecosystems and their fauna. Although the various effects of pesticides on biodiversity have been already documented in several studies, to our knowledge no consistent overview of the impact of pesticides in vertebrates, both terrestrial and aquatic, is available. In this review, we try to present a concise compilation of the teratogenic effects of pesticides on the different classes of vertebrates – mammals, birds, reptiles, amphibians and fish.     

Radionuclides in pinon pine (Pinus edulis) nuts from los alamos national laboratory lands and the dose from consumption

Abstract

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of ³H, ¹³⁷Cs, ⁹⁰Sr, ^totU, ²³⁸Pu, ^{239, 240}Pu, and²⁴¹ Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of ³H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.     

Degradation and sorption of imidacloprid in dissimilar surface and subsurface soils

Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. This research characterized the degradation and sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) in Drummer (silty clay loam) and Exeter (sandy loam) surface soils and their corresponding subsurface soils using sequential extraction methods over 400 days. By the end of the incubation, approximately 55% of imidacloprid applied at a rate of 1.0 mg kg^?1 degraded in the Exeter sandy loam surface and subsurface soils, compared to 40% of applied imidacloprid within 300 days in Drummer surface and subsurface soils. At the 0.1 mg kg^?1 application rate, dissipation was slower for all four soils. Water-extractable imidacloprid in Exeter surface soil decreased from 98% of applied at day 1 to > 70% of the imidacloprid remaining after 400 d, as compared to 55% in the Drummer surface soil at day 1 and 12% at day 400. These data suggest that imidacloprid was bioavailable to degrading soil microorganisms and sorption/desorption was not the limiting factor for biodegradation. In subsurface soils > 40% of ¹⁴C-benzoic acid was mineralized over 21 days, demonstrating an active microbial community. In contrast, cumulative ¹⁴CO₂ was less than 1.5% of applied ¹⁴C-imidacloprid in all soils over 400 d. Qualitative differences in the microbial communities appear to limit the degradation of imidacloprid in the subsurface soils.